Communication method, apparatus, storage medium, and program product

Abstract

Embodiments of the present disclosure provide a communication method, device, storage medium and program product, relating to the technical field of communication, and used for guaranteeing the reliability of a service when a remote terminal switches. The method is applied to a first base station, and includes sending first request information to a second base station, the first request information being used for requesting to add or replace an indirect path for the remote terminal; and receiving first response information sent by the second base station, the first response information being used for indicating whether to agree to add or replace the indirect path for the remote terminal.

Description

Technical Field

[0001] This disclosure relates to the field of communication technology, and in particular to a communication method, apparatus, storage medium, and program product. Background Technology

[0002] Release 18 of the 3rd Generation Partnership Project (3GPP) introduced user equipment (UE) aggregation, where a UE (remote UE or anchor UE) connects to the base station via a direct path and connects to the network via a non-standardized UE-UE interconnect (relay UE or aggregated UE). This non-standardized interconnection between UEs is called a non-3GPP connection (N3C). UE aggregation aims to provide 5G terminals with applications requiring high uplink bit rates, especially at cell edges where ordinary UEs are limited by uplink UE transmission power and cannot achieve the required bit rates. Furthermore, UE aggregation can improve service reliability and stability and reduce latency; that is, if the channel conditions of one terminal deteriorate, another terminal can be used to compensate for the unstable traffic performance caused by changes in channel conditions.

[0003] However, currently, when a remote terminal switches over, the reliability of the service cannot meet the requirements or be guaranteed. Summary of the Invention

[0004] This disclosure provides a communication method, apparatus, storage medium, and program product to ensure service reliability when a remote terminal switch occurs.

[0005] To achieve the above objectives, the present disclosure adopts the following technical solution.

[0006] Firstly, a communication method is provided, applied to a first base station, the method comprising:

[0007] Send a first request message to the second base station. The first request message is used to request the addition or replacement of the indirect path for the remote terminal.

[0008] The system receives a first response message sent by the second base station. The first response message indicates whether the system agrees to add or change the indirect path for the remote terminal.

[0009] Secondly, a communication method is provided for use with a second base station, the method comprising:

[0010] Receive a first request information sent by the first base station, the first request information being used to request the addition or replacement of an indirect path for the remote terminal;

[0011] Send a first response message to the first base station. The first response message is used to indicate whether you agree to add or change the indirect path for the remote terminal.

[0012] Thirdly, a communication method is provided for use in a remote terminal, the method comprising:

[0013] Receive first configuration information sent by the first base station, the first configuration information being used to configure at least one of the following:

[0014] Remote terminal can add / modify / change indirect paths;

[0015] The identifier of the relay terminal to be added / modified / replaced.

[0016] Fourthly, a communication method is provided, applied to a first base station, the method comprising:

[0017] Send a second request message to the second base station. The second request message is used to request that the direct path of the remote terminal be changed to the second base station. The remote terminal connects to the first base station through the direct path and the indirect path.

[0018] The system receives a second response message sent by the second base station, which indicates whether it agrees to change the direct path of the remote terminal to the second base station.

[0019] Fifthly, a communication method is provided for use in a second base station, the method comprising:

[0020] The system receives a second request message sent by the first base station. The second request message is used to request that the direct path of the remote terminal be changed to the second base station. The remote terminal connects to the first base station through a direct path and an indirect path.

[0021] A second response message is sent to the first base station, which indicates whether the direct path of the remote terminal is changed to the second base station.

[0022] Sixthly, a communication method is provided, applied to a first base station, the method comprising:

[0023] Send a second indication message to the second base station. The second indication message is used to indicate the association or aggregation relationship between the remote terminal and the relay terminal. The remote terminal connects to the first base station through a direct path and an indirect path.

[0024] Receive the third response information sent by the second base station.

[0025] Seventhly, a communication method is provided for use in a second base station, the method comprising:

[0026] The system receives a second indication information sent by the first base station. The second indication information is used to indicate the association or aggregation relationship between the remote terminal and the relay terminal. The remote terminal connects to the first base station through a direct path and an indirect path.

[0027] Send a third response message to the second base station.

[0028] Eighthly, a communication method is provided for use in a remote terminal, the method comprising:

[0029] In response to a handover failure, a third indication message is sent to the first base station via an indirect path or a split signaling radio bearer. The third indication message is used to indicate a handover failure. The remote terminal connects to the first base station via a direct path and an indirect path. During the handover process of the remote terminal, the remote terminal maintains data transmission on the indirect path with the first base station and accesses the second base station via the direct path.

[0030] Ninth aspect, a communication device is provided for use in a first base station, comprising:

[0031] The sending unit is used to send a first request information to the second base station. The first request information is used to request the addition or replacement of the indirect path for the remote terminal.

[0032] The receiving unit is used to receive first response information sent by the second base station. The first response information is used to indicate whether it agrees to add or change the indirect path for the remote terminal.

[0033] A tenth aspect provides a communication device for use in a second base station, comprising:

[0034] The receiving unit is used to receive a first request information sent by the first base station, the first request information being used to request the addition or replacement of an indirect path for the remote terminal.

[0035] The sending unit is used to send first response information to the first base station. The first response information is used to indicate whether it agrees to add or change the indirect path for the remote terminal.

[0036] Eleventhly, a communication device is provided for use in a remote terminal, comprising:

[0037] The receiving unit is configured to receive first configuration information sent by the first base station, wherein the first configuration information is used to configure at least one of the following:

[0038] Remote terminal can add / modify / change indirect paths;

[0039] The identifier of the relay terminal to be added / modified / replaced.

[0040] In a twelfth aspect, a communication device is provided, applied to a first base station, comprising:

[0041] The sending unit is used to send a second request message to the second base station. The second request message is used to request that the direct path of the remote terminal be changed to the second base station. The remote terminal connects to the first base station through a direct path and an indirect path.

[0042] The receiving unit is used to receive second response information sent by the second base station. The second response information is used to indicate whether it agrees to change the direct path of the remote terminal to the second base station.

[0043] In a thirteenth aspect, a communication device is provided for use in a second base station, comprising:

[0044] The receiving unit is used to receive a second request information sent by the first base station. The second request information is used to request that the direct path of the remote terminal be changed to the second base station. The remote terminal connects to the first base station through a direct path and an indirect path.

[0045] The sending unit is used to send a second response information to the first base station, the second response information being used to indicate whether it agrees to change the direct path of the remote terminal to the second base station.

[0046] In a fourteenth aspect, a communication device is provided, applied to a first base station, comprising:

[0047] The transmitting unit is used to send second indication information to the second base station. The second indication information is used to indicate the association or aggregation relationship between the remote terminal and the relay terminal. The remote terminal is connected to the first base station through a direct path and an indirect path.

[0048] The receiving unit is used to receive the third response information sent by the second base station.

[0049] In a fifteenth aspect, a communication device is provided for use in a second base station, comprising:

[0050] The receiving unit is used to receive second indication information sent by the first base station. The second indication information is used to indicate the association or aggregation relationship between the remote terminal and the relay terminal. The remote terminal is connected to the first base station through a direct path and an indirect path.

[0051] The sending unit is used to send third response information to the second base station.

[0052] In a sixteenth aspect, a communication device is provided for use in a remote terminal, comprising:

[0053] The transmitting unit is used to send third indication information to the first base station via an indirect path or a split signaling radio bearer in response to a handover failure. The third indication information is used to indicate a handover failure. The remote terminal is connected to the first base station via a direct path and an indirect path. During the handover process of the remote terminal, the remote terminal maintains data transmission on the indirect path with the first base station and accesses the second base station via the direct path.

[0054] In a seventeenth aspect, a communication device is provided, comprising: a processor and a memory; the memory and the processor are coupled; the memory is used to store processor-executable instructions, the memory storing processor-executable instructions; when the processor is configured to execute the instructions, the communication device performs the method provided by any one of the first to eighth aspects described above.

[0055] Eighteenth aspect: A computer-readable storage medium is provided that stores computer instructions, which, when executed on a computer, cause the computer to perform the methods provided by any one of the first to eighth aspects described above.

[0056] Nineteenth aspect: A computer program product comprising computer instructions, which, when executed on a computer, cause the computer to perform the method provided by any one of the first to eighth aspects described above.

[0057] In this embodiment of the disclosure, the first base station sends a first request message to the second base station to request the addition or replacement of an indirect path for the remote terminal, and then receives a first response message from the second base station. The first response message indicates whether it agrees to add or replace the indirect path for the remote terminal. This means that in this embodiment of the disclosure, the remote terminal supports simultaneous access to the first base station and the second base station. That is, the remote terminal can access the first base station through a direct path and access the second base station through a relay terminal on an indirect path. In other words, the remote terminal and the relay terminal do not need to be under the same base station. Thus, when the remote terminal performs a cross-base station handover, the service will not be interrupted, and the reliability, stability and latency of the service can be guaranteed. Attached Figure Description

[0058] The accompanying drawings are provided to further understand the technical solutions of this disclosure and constitute a part of the specification. They are used together with the embodiments of this disclosure to explain the technical solutions of this disclosure and do not constitute a limitation on the technical solutions of this disclosure.

[0059] Figure 1 This is a schematic diagram of UE aggregation provided in an embodiment of the present disclosure;

[0060] Figure 2 This is a schematic diagram of the structure of a communication system provided in an embodiment of the present disclosure;

[0061] Figure 3 A flowchart illustrating a communication method provided in an embodiment of this disclosure;

[0062] Figure 4 A flowchart illustrating another communication method provided in an embodiment of this disclosure;

[0063] Figure 5 A flowchart illustrating another communication method provided in an embodiment of this disclosure;

[0064] Figure 6 This is a schematic diagram of the overall process of a communication method provided in an embodiment of the present disclosure;

[0065] Figure 7 This is a schematic diagram of the overall process of another communication method provided in an embodiment of the present disclosure;

[0066] Figure 8 A flowchart illustrating another communication method provided in an embodiment of this disclosure;

[0067] Figure 9 A flowchart illustrating another communication method provided in an embodiment of this disclosure;

[0068] Figure 10 This is a schematic diagram of the overall process of another communication method provided in an embodiment of the present disclosure;

[0069] Figure 11 A flowchart illustrating another communication method provided in an embodiment of this disclosure;

[0070] Figure 12 A flowchart illustrating another communication method provided in an embodiment of this disclosure;

[0071] Figure 13 A flowchart illustrating another communication method provided in an embodiment of this disclosure;

[0072] Figure 14 This is a schematic diagram of the composition of a communication device provided in an embodiment of the present disclosure;

[0073] Figure 15 A schematic diagram illustrating the composition of another communication device provided in an embodiment of this disclosure;

[0074] Figure 16 A schematic diagram illustrating the composition of another communication device provided in an embodiment of this disclosure;

[0075] Figure 17 A schematic diagram illustrating the composition of another communication device provided in an embodiment of this disclosure;

[0076] Figure 18 A schematic diagram illustrating the composition of another communication device provided in an embodiment of this disclosure;

[0077] Figure 19 A schematic diagram illustrating the composition of another communication device provided in an embodiment of this disclosure;

[0078] Figure 20 A schematic diagram illustrating the composition of another communication device provided in an embodiment of this disclosure;

[0079] Figure 21 A schematic diagram illustrating the composition of another communication device provided in an embodiment of this disclosure;

[0080] Figure 22 This is a schematic diagram of the structure of a communication device provided in an embodiment of this disclosure. Detailed Implementation

[0081] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this disclosure.

[0082] Unless the context otherwise requires, throughout the specification and claims, the term "comprise" and other forms such as the third-person singular "comprises" and the present participle "comprising" are interpreted as open-ended and encompassing, meaning "including, but not limited to." In the description of the specification, terms such as "one embodiment," "some embodiments," "exemplary embodiments," "example," "specific example," or "some examples" are intended to indicate that a particular feature, structure, material, or characteristic associated with that embodiment or example is included in at least one embodiment or example of this disclosure. The illustrative representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics mentioned may be included in any suitable manner in any one or more embodiments or examples.

[0083] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this disclosure, unless otherwise stated, "a plurality of" means two or more.

[0084] In this disclosure, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design described as "exemplary" or "for example" in this disclosure should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0085] In addition, the use of “based on” implies openness and inclusivity, because processes, steps, calculations or other actions “based on” one or more of the stated conditions or values ​​may in practice be based on additional conditions or values ​​beyond those stated.

[0086] 3GPP Release 18 introduced UE aggregation technology. Figure 1 This is a schematic diagram of UE aggregation provided in an embodiment of the present disclosure. The remote terminal uses a direct path (i.e. Figure 1 Path 1) and an indirect path (i.e. Figure 1 In path 2), the multi-path relay terminal connects to the network. The indirect path can also be called the indirect path, and there are multi-path (MP) relay terminals on the indirect path. However, currently, it is restricted that the remote terminal and the relay terminal must be under the same base station. Therefore, when the remote terminal undergoes a cross-base station handover, the reliability, stability, and latency of the service cannot meet the requirements / cannot be guaranteed.

[0087] Based on this, embodiments of this disclosure provide a communication method, apparatus, storage medium, and program product. A first base station sends a first request message to a second base station to request the addition or replacement of an indirect path for a remote terminal, and then receives a first response message sent by the second base station. The first response message indicates whether it agrees to add or replace the indirect path for the remote terminal. This means that in embodiments of this disclosure, the remote terminal supports simultaneous access to the first base station and the second base station. That is, the remote terminal can access the first base station through a direct path and access the second base station through a relay terminal on an indirect path. In other words, the remote terminal and the relay terminal do not need to be under the same base station. Thus, when the remote terminal performs a cross-base station handover, the service will not be interrupted, and the reliability, stability, and latency of the service can be guaranteed.

[0088] The embodiments of this disclosure will now be described in conjunction with the accompanying drawings.

[0089] The technical solutions provided in this disclosure can be applied to various mobile communication networks, such as New Radio (NR) mobile communication networks using 5th generation mobile networks (5G), future mobile communication networks, or multiple communication convergence systems, etc. This disclosure does not limit these applications.

[0090] Figure 2 The diagram shown is a schematic representation of the architecture of a communication system provided in an embodiment of this disclosure. Figure 2 As shown, the communication system includes multiple base stations (e.g., base station 21, base station 22, and base station 23) and multiple terminals (e.g., terminal 31, terminal 32, terminal 33, and terminal 34). The base stations and terminals can be communicatively connected. Terminals can connect to each other via PC5 ports, and terminals can connect to base stations via Uu ports.

[0091] A terminal can connect to the same base station through both direct and indirect paths, or it can connect to one base station through a direct path and to another base station through an indirect path.

[0092] Taking terminal 31 as a remote terminal as an example, in the UE aggregation scenario under the same base station, terminal 31 can connect to base station 21 through a direct path and connect to base station 21 through an indirect path via terminal 32.

[0093] Taking terminal 33 as a remote terminal as an example, in the UE aggregation scenario across base stations, terminal 33 can connect to base station 22 through a direct path and connect to base station 23 through the indirect path of terminal 34.

[0094] In this disclosure, the base station can be a base station in Long Term Evolution (LTE), Long Term Evolution Advanced (LTEA), or an evolved Node B (eNB or eNodeB), a base station device in a 5G network, or a base station in a future communication system (such as 6G). The base station can include various macro base stations, micro base stations, femtocell base stations, wireless remote extensions, reconfigurable intelligent surfaces (RISs), routers, wireless Fidelity (WIFI) devices, or various network-side devices such as primary cells and secondary cells.

[0095] In this disclosure, the terminal is a device with wireless transceiver capabilities, which can be deployed on land, including indoors or outdoors, handheld, wearable, or vehicle-mounted; it can also be deployed on water (such as on ships); and it can also be deployed in the air (e.g., on airplanes, balloons, and satellites). The terminal can be a mobile phone, tablet computer, computer with wireless transceiver capabilities, virtual reality (VR) terminal, augmented reality (AR) terminal, wireless terminal in industrial control, wireless terminal in self-driving, wireless terminal in remote medical care, wireless terminal in smart grid, wireless terminal in transportation safety, wireless terminal in smart city, wireless terminal in smart home, etc. The embodiments of this disclosure do not limit the application scenarios. A terminal may also be referred to as a user, user equipment (UE), access terminal, UE unit, UE station, mobile station, mobile station, remote station, remote terminal, mobile device, UE terminal, wireless communication equipment, UE agent, or UE device, etc. The embodiments disclosed herein are not limited.

[0096] It should be understood that Figure 2 This is an exemplary structural diagram. Figure 2 The number of devices included in the illustrated communication system is unlimited; for example, the number of terminals and base stations is unlimited. Furthermore, except... Figure 2 In addition to the equipment shown, Figure 2 The communication system shown may also include other devices, which are not limited thereto.

[0097] Next, as Figure 3 As shown in the embodiments of this disclosure, a communication method is provided, which is applied to a first base station, and the method includes the following steps:

[0098] S101, Send the first request information to the second node.

[0099] The first request information is used to request the addition or replacement of an indirect path for the remote terminal. The remote terminal is connected to the first base station via a direct path and / or an indirect path. The second base station is either a base station to which the remote terminal is connected, or a base station to which the remote terminal is not connected. For example, if the second base station is a base station to which the remote terminal is connected, the first request information is used to request the replacement of the indirect path for the remote terminal. If the second base station is a base station to which the remote terminal is not connected, the first request information is used to request the addition of an indirect path for the remote terminal.

[0100] Combination Figure 2 In the communication system shown, taking terminal 31 as an example, the first base station can be base station 21 and the second base station can be base station 22.

[0101] The first base station may have other names, such as the source base station. The second base station may also have other names, such as the target base station; this disclosure does not limit this.

[0102] Based on the above description of UE aggregation, cross-base station UE aggregation and cross-base station path management can be considered. For example, originally, remote terminals and relay terminals are aggregated under the first base station. Due to the relocation of the relay terminal or other reasons, the original indirect path / relay terminal may be released, and the remote terminal may be configured with a relay terminal under another base station (i.e., the second base station) for UE aggregation. Alternatively, due to the relocation of the remote terminal, the source-side indirect path may be retained, while switching to a direct path under another base station. Supporting these cross-base station path management methods allows for more flexible handling of various UE aggregation or mobility scenarios.

[0103] Path management across base stations needs to consider things like adding or replacing indirect paths and replacing direct paths.

[0104] In some embodiments, the scenarios for adding or changing indirect paths for remote terminals include any of the following:

[0105] Scenario 1: When a remote terminal is connected to the first base station via a direct path, add an indirect path to the second base station for the remote terminal.

[0106] For scenario 1, where the remote terminal connects to the first base station only via a direct path, an indirect path under the second base station is added to the remote terminal. Based on this, the first request information is used to request the addition of an indirect path to the remote terminal.

[0107] Scenario 2: When a remote terminal is connected to the first base station via a direct path and an indirect path, the remote terminal is switched to the indirect path under the second base station while maintaining the direct path under the first base station.

[0108] In scenario 2, where the remote terminal connects to the first base station via both direct and indirect paths, the indirect path under the second base station is changed for the remote terminal (while retaining the direct path under the first base station). Compared to scenario 1, scenario 2 achieves the replacement of the relay terminal in one process (rather than releasing the source relay terminal first and then adding the new relay terminal).

[0109] Scenario 3: When a remote terminal connects to the first base station via a direct path and to the second base station via an indirect path, the indirect path for the remote terminal to be switched to another relay terminal under the second base station is changed, while maintaining the direct path with the first base station.

[0110] For scenario 3, where the remote terminal connects to the first base station via a direct path and to the second base station via a relay terminal / indirect path, the indirect path is switched to another relay terminal under the second base station while maintaining the direct path with the first base station. Based on this, the first request information is used to request switching the remote terminal to another relay terminal under the second base station via an indirect path. After receiving the first request information, the second base station can determine whether to agree to switch the remote terminal to another relay terminal under the second base station via an indirect path. If it agrees, the remote terminal can be switched to another relay terminal under the second base station via an indirect path.

[0111] Scenario 4: When a remote terminal connects to the first base station via a direct path and to the third base station via an indirect path, the remote terminal is switched to the indirect path under the second base station while maintaining the direct path under the first base station. In Scenario 4, the second base station may be a base station that has not yet established a connection with the remote terminal.

[0112] For scenario 4, where the remote terminal connects to the first base station via a direct path and to the third base station via a relay terminal / indirect path, the indirect path of the remote terminal is changed to a relay terminal under the second base station. In other words, the indirect path of the relay terminal is changed from the currently connected base station to another base station. Based on this, the first request information is used to request that the indirect path of the remote terminal be changed to a relay terminal under the second base station. After receiving the first request information, the second base station can determine whether to agree to change the indirect path of the remote terminal to a relay terminal under the second base station. If it agrees, the remote terminal can be changed to a relay terminal under the second base station.

[0113] It should be noted that, in scenario 4, the first base station can also send an instruction message to the third base station instructing it to release the original indirect path. After receiving the instruction message, the third base station can release the original indirect path.

[0114] The remote terminal connects to the first base station via a direct path, adding an indirect path for the remote terminal; that is, the remote terminal connects to the first base station via a direct path and to the second base station via an indirect path, equivalent to dual connectivity for the remote terminal. The remote terminal maintains radio resource control (RRC), service data adaptation protocol (SDAP), and packet data convergence protocol (PDCP) for the master node (MN) (MN being the base station of the direct path) and the secondary node (SN) (SN being the base station of the indirect path) respectively. In other words, the PDCP for MN and SN are independent and complete.

[0115] As an example, sending a first request message to the second base station includes:

[0116] Obtain a measurement report, which includes the identifier of at least one candidate relay terminal and the serving cell; based on the measurement report, determine whether to add or change the indirect path between the remote terminal and the second base station; in response to determining whether to add or change the indirect path between the remote terminal and the second base station, send a first request message to the second base station.

[0117] The acquisition of the measurement report can be achieved by receiving a measurement report sent by a remote terminal, or by the first base station generating a measurement report. This embodiment of the present disclosure does not limit the implementation method of acquiring the measurement report.

[0118] The identifier of a candidate relay terminal includes its cell-radionetwork temporary identifier (C-RNTI).

[0119] In other words, after the first base station (source base station) receives the measurement report (containing the C-RNTI and serving cell of one or more candidate relay terminals), it can decide whether to add an inter-gNB indirect path (under another base station), and the first base station determines the target base station (i.e., the second base station) / target cell.

[0120] When it is determined whether to add or change an indirect path, the first base station sends the information of candidate relay terminals for the target base station (i.e., the second base station) / target cell to the second base station. The first base station can send information on all or a subset of candidate relay terminals to the second base station; this information can be a priority list recommended by the first base station. Alternatively, the first base station can select and decide on the candidate relay terminals / candidate indirect paths and send the information of the selected candidate relay terminals to the second base station. The transmission method needs to consider whether to use existing Xn messages (e.g., handover (HO) request messages, SN addition request messages) or introduce new Xn procedures (e.g., Xn interface multipath addition request messages).

[0121] For requests to add or change indirect paths for remote terminals, the following examples may be included:

[0122] Example 1: When the first request information is used to request the addition of an indirect path for a remote terminal, the first request information is carried in any of the following: a secondary node addition request message (i.e., an SN addition request message) or an Xn interface multipath addition request message; wherein the secondary node addition request message and the Xn interface multipath addition request message include a candidate relay UE list.

[0123] Taking the first request information carried in the secondary node add request message as an example, the secondary node add request message also includes at least one of the following:

[0124] Add an indicator to the indirect path;

[0125] Source indirect path related information;

[0126] Identification of the source relay terminal;

[0127] Bearer mapping, where the bearer mapping is the mapping relationship between the data radiobearer (DRB) of the remote terminal under the first base station and the Uu relay radio link control (RLC) channel of the source relay terminal.

[0128] Uu relay RLC channel configuration.

[0129] In some embodiments, the secondary node addition request message further includes a secondary node addition triggering reason, which includes at least one of the following:

[0130] Adding / modifying / switching indirect paths in multipath communication;

[0131] N3C indirect path addition / modification / switching;

[0132] Adding / modifying / switching indirect paths via sidelinks (SL);

[0133] The reason for changing the indirect path includes at least one of the following:

[0134] The N3C interface of the source indirect path fails; the PC5 link quality of the source indirect path is less than the first threshold; the PC5 link of the source indirect path experiences radio link failure (RLF); the relay terminal on the source indirect path experiences Uu RLF; the Uu link quality of the relay terminal on the source indirect path is less than the second threshold; and the Uu connection establishment / recovery of the relay terminal on the source indirect path fails.

[0135] In some embodiments, the reason for changing the indirect path also includes the MN negotiating with the SN to configure the terminated bearers of the MN / SN.

[0136] Among them, SN terminated bearers include secondary cell group (SCG) bearers - indirect path bearers (without MN participation) and SN terminated split bearers, which are equivalent to the primary path (i.e., indirect path) of the split bearer being in the SN, and being transmitted to the SN via the source side direct path and forwarded by the MN (requiring MN participation, included in the response message).

[0137] MN terminated bearers: These include offloaded bearers that require SN participation for MN termination. This means that the main path (indirect path) of the offloaded bearer is on the MN, and it is transmitted through the indirect path on the target side and forwarded to the MN by the SN.

[0138] In some embodiments, when using a secondary node add request message, a list of candidate relay terminals is introduced in the message. This message may contain candidate relay terminals from multiple cells under the second base station. Each candidate relay terminal in the list contains at least one of the following: the relay terminal's identifier (e.g., the UE XnAP ID, C-RNTI, aggregated UE identifier, or N3C relay terminal identifier under the first base station). It also requests the second base station to allocate resources for one or more packet data unit (PDU) sessions / Quality of Service (QoS) flows, negotiate the configuration of bearers terminated by the MN / SN, and may use existing signaling.

[0139] Taking the first request information carried in the Xn interface multipath addition request message as an example, the message introduces a list of candidate relay terminals. It also requests the second reception letter to allocate resources for one or more PDU sessions / QoS flows and negotiate the configuration of MN / SN-terminated bearers.

[0140] In some embodiments, where the first request information is used to request the addition of an indirect path for a remote terminal, the first request information can also be carried in a HO request message. It is necessary to distinguish whether the indication is a request for path transformation or a request to add an indirect path. For example, the HO request message may introduce 1 bit to indicate the addition of an indirect path / MP operation. Furthermore, a new 1 bit may be added to reconfigure with synchronization (reconfigWithSync) to indicate the addition of an indirect path, or an indirect path addition list may be introduced to contain information about the newly added relay terminal.

[0141] Example 2: When the first request information is used to request a change of indirect path for a remote terminal, the first request information is carried in any of the following ways:

[0142] SN modification request messages include messages requiring SN modification, SN change required, and SN release required. These messages all include a reason for changing the indirect path, which must include at least one of the following:

[0143] The N3C interface of the source indirect path failed; the PC5 link quality of the source indirect path was less than the first threshold; an RLF occurred in the source indirect path; a Uu RLF occurred in the relay terminal on the source indirect path; the Uu link quality of the relay terminal on the source indirect path was less than the second threshold; and the Uu connection establishment / recovery of the relay terminal on the source indirect path failed.

[0144] It should be noted that any of the three messages—needing to modify the SN, needing to replace the SN, or needing to release the SN—can be sent by the remote terminal from a base station connected via an indirect path to a base station connected via a direct path. However, the first request information is sent from the first base station to the second base station. Therefore, when the first request information carries any one of these three messages, the first base station is the base station connected to the remote terminal via an indirect path, and the second base station is the base station connected to the remote terminal via a direct path. In other words, the first request information carrying any one of these three messages corresponds to an indirect path replacement / modification process initiated by the base station connected to the remote terminal via an indirect path.

[0145] In other words, when the first request information is carried in an SN modification request message, the first base station is a base station directly connected to by the remote terminal via a direct path, and the second base station is a base station indirectly connected to by the remote terminal via an indirect path. Alternatively, when the first base station is a base station indirectly connected to by the remote terminal via an indirect path, and the second base station is a base station directly connected to by the remote terminal via a direct path, the first request information is carried in any of the following: a SN modification message, a SN replacement message, or a SN release message.

[0146] Based on this, when the first request information carries any one of the following: needing to modify the SN message, needing to replace the SN message, or needing to release the SN message, the above scenarios for adding or changing indirect paths for remote terminals can also include:

[0147] When a remote terminal connects to the second base station via a direct path and to the first base station via an indirect path, the indirect path for the remote terminal to be switched to another relay terminal under the first base station is changed.

[0148] When a remote terminal connects to the second base station via a direct path or to the third base station via an indirect path, the remote terminal is switched to the first base station.

[0149] For the indirect path to another relay terminal under the base station connected to the remote terminal via an indirect path, the following methods may be included.

[0150] 1) In one approach, a remote terminal can initiate a process to change / modify the indirect path from a base station directly connected to it to a base station indirectly connected to it. Taking the base station directly connected to the remote terminal as the first base station and the base station indirectly connected as the second base station as an example, the first base station can initiate a process to change / modify the indirect path to the second base station, i.e., change the indirect path to another relay terminal under the second base station. For example, the first base station sends an SN modification request message to the second base station, which includes a list of candidate relay terminals or recommended candidate relay terminals, and may also include the reason for changing the indirect path: such as N3C failure (of the source indirect path), PC5 link quality below the configured threshold or RLF occurrence, Uu RLF occurrence of the relay terminal in the source indirect path, Uu link quality below the configured threshold, or Uu connection establishment / recovery failure.

[0151] 2) Alternatively, a remote terminal can initiate a process to change / modify the indirect path from a base station connected via an indirect path to a base station connected via a direct path. Taking the first base station as an example where the remote terminal is connected via an indirect path and the second base station as an example where the remote terminal is connected via a direct path. For instance, the first base station sends an SN modification required message to the second base station, which includes the identifier of the new / target relay terminal and may also include the reason for changing the indirect path: such as N3C failure (of the source indirect path), PC5 link quality below the configured threshold or RLF occurrence, Uu RLF occurrence, handover, Uu link quality below the configured threshold, Uu connection establishment / recovery failure, or high load on the relay terminal of the source indirect path.

[0152] The above-mentioned method of switching a remote terminal to another base station can include the following:

[0153] Method 1) The remote terminal initiates an indirect path addition process to the base station that is directly connected to the remote terminal through the base station, which is not connected to the remote terminal. Similar to Example 1 above, the base station that the remote terminal is directly connected to is the first base station, and the base station that is not connected to the remote terminal is the second base station. The first base station sends an SN addition request message to the second base station, which includes information such as the candidate relay terminal list.

[0154] Method 2) The remote terminal sends an SN change required message to a base station directly connected to it via a direct path. Taking the base station indirectly connected to the remote terminal as the first base station and the base station directly connected as the second base station as the second base station, the first base station sends an SN change required message to the second base station, which includes (at least one of the following): the identifier of the target base station (the base station not connected to the remote terminal), a list of candidate relay terminals, an indication to change the indirect path, and the reason for changing the indirect path. Then, the second base station sends an SN addition request message to the other base station, which includes information such as the list of candidate relay terminals.

[0155] 3) A remote terminal sends an SN release required message to a base station connected via an indirect path to a base station connected via a direct path. Taking the base station connected via the indirect path as the first base station and the base station connected via the direct path as the second base station as an example, the first base station sends an SN release required message to the second base station. This message includes the reason for releasing the indirect path: such as N3C identification (of the source indirect path), PC5 link quality falling below the configured threshold or experiencing RLF, Uu RLF occurring at a relay terminal on the source indirect path, handover occurring, Uu link quality falling below the configured threshold, Uu connection establishment / recovery failure, or high load on the relay terminal on the source indirect path. Upon receiving the SN release required message, the second base station decides whether to add a new indirect path.

[0156] It should be noted that the SN addition request / response message, SN modification request / response message, SN modification required message, SN change required message, and SN release required message can also be messages introduced by the Xn interface specifically for multi-path addition / modification / replacement / release related messages.

[0157] S102, Receive the first response information sent by the second base station.

[0158] The first response information is used to indicate whether or not to agree to add or change the indirect path for the remote terminal.

[0159] In some embodiments, when the first request information is carried in the SN add request message, the first response information is carried in the SN add response message.

[0160] Taking the first request information used to request the addition of an indirect path for a remote terminal as an example, after receiving the first request information, the second base station can select / determine the target relay terminal, i.e., the indirect path to be added. The second base station interacts with the selected target relay terminal to prepare for adding the indirect path. Afterwards, the second base station replies to the first base station with a first response message, which includes the identifier of the selected target relay terminal and the MN / SN terminated bearer negotiation result; and informs the remote terminal of the selected target relay terminal (included in the RRC configuration message generated by the second base station).

[0161] After receiving the first response information, the first base station sends an RRC reconfiguration message (i.e., the first configuration information below) to the remote terminal, indicating the addition of an indirect path (including the identifier of the target relay terminal).

[0162] After receiving the RRC reconfiguration message, the remote terminal determines whether to accept the configuration and replies with a response message to the first base station. The remote terminal associates with / establishes a connection with the target relay terminal. If split signaling radio bearer 1 (SRB1) / SRB3 is configured, the remote terminal can further send an SN RRC response message to the SN via an indirect path. The split SRB1 can be a duplicated split SRB1.

[0163] For the SN terminated bearer, perform Xn data forwarding / SN status transfer to update the user plane path with the core network.

[0164] Taking the example of the first request information being used to request a change of indirect path for a remote terminal, and the first response information being carried in the SN add response message, the second base station (SN) selects the target relay terminal and interacts with it, informing it of the addition of an indirect path for the remote terminal, as well as the Uu relay RLC channel configuration and bearer mapping configuration. The second base station then replies to the first base station with the SN add response message.

[0165] After receiving the SN add response message, the first base station can send an RRC reconfiguration message to the source relay terminal, instructing the source relay terminal to release the indirect path related to the remote terminal. This can be sent later, for example, after receiving the RRC reconfiguration completion message from the remote terminal, so that the source relay terminal can forward the cached uplink (UL) data from the remote terminal. Afterward, the first base station will no longer send downlink (DL) data to the remote terminal through the source indirect path. It can still receive uplink data from the remote terminal forwarded by the source relay terminal. Whether the source relay terminal immediately performs configuration release upon receiving the configuration, or waits until the cached UL data from the remote terminal is forwarded before replying with a response message, can be implemented by the UE.

[0166] After receiving the SN add response message, the first base station sends an RRC reconfiguration message (i.e., the first configuration information) to the remote terminal, configuring the remote terminal to perform indirect path replacement and indicating the identifier of the new relay terminal. The remote terminal stops sending uplink data on the source indirect path. An end marker can be sent on each DRB on the indirect path so that the first base station knows that the relay terminal on the source indirect path has completed forwarding the remote terminal's uplink data. The remote terminal and the source relay terminal release their association relationship (N3C out of scope) and no longer send data to each other. The source relay terminal also stops forwarding downlink data to the remote terminal.

[0167] The remote terminal associates with the target relay terminal. The remote terminal sends an RRC reconfiguration complete message to the first base station. After receiving the RRC reconfiguration complete message from the remote terminal, the first base station sends an SN reconfiguration complete message to the second base station. If a traffic splitter SRB1 or SRB3 with replication is configured, the remote terminal also sends an RRC reconfiguration complete message to the second base station through the target relay terminal.

[0168] Based on the above description, after receiving the first response message, the first base station can send first configuration information to the remote terminal. The first configuration information is used to configure at least one of the following:

[0169] Remote terminal can add / modify / change indirect paths;

[0170] The identifier of the relay terminal to be added / modified / replaced. The relay terminal to be added / modified / replaced is the target relay terminal mentioned above.

[0171] based on Figure 3In the illustrated embodiment, the first base station sends a first request message to the second base station to request the addition or replacement of an indirect path for the remote terminal, and then receives a first response message from the second base station. The first response message indicates whether it agrees to add or replace the indirect path for the remote terminal. This means that in this embodiment, the remote terminal supports simultaneous access to the first base station and the second base station. That is, the remote terminal can access the first base station through a direct path and access the second base station through a relay terminal on an indirect path. In other words, the remote terminal and the relay terminal do not need to be under the same base station. Thus, when the remote terminal performs a cross-base station handover, the service will not be interrupted, and the reliability, stability and latency of the service can be guaranteed.

[0172] In some embodiments, such as Figure 4 As shown in the embodiments of this disclosure, another communication method is also provided, applied to a second base station, which may include the following steps:

[0173] S201, Receive the first request information sent by the first base station.

[0174] The first request information is used to request the addition or replacement of indirect paths for remote terminals.

[0175] For a description of the first request information, please refer to the above. Figure 3 The corresponding descriptions in the illustrated embodiments are not repeated here.

[0176] In some embodiments, the first request information includes information about the candidate relay terminal.

[0177] In some embodiments, where the first request information is used to request the addition of an indirect path for a remote terminal, the first request information is carried in any of the following ways:

[0178] The secondary node adds a request message, and the Xn interface multipath adds a request message; the secondary node adds a request message and the Xn interface multipath adds a request message, which include a list of candidate relay terminals.

[0179] In some embodiments, the secondary node add request message further includes at least one of the following:

[0180] Add an indicator to the indirect path;

[0181] Source indirect path related information;

[0182] Identification of the source relay terminal;

[0183] Bearer mapping;

[0184] Uu relay RLC channel configuration.

[0185] In some embodiments, the secondary node addition request message further includes a secondary node addition triggering reason, which includes at least one of the following:

[0186] Adding / modifying / switching indirect paths in multipath communication;

[0187] N3C indirect path addition / modification / switching;

[0188] SL indirect path addition / modification / switching;

[0189] The reason for changing the indirect path includes at least one of the following:

[0190] The N3C interface of the source indirect path failed; the PC5 link quality of the source indirect path was less than the first threshold; the PC5 link of the source indirect path experienced RLF; the relay terminal on the source indirect path experienced Uu RLF; the Uu link quality of the relay terminal on the source indirect path was less than the second threshold; and the Uu connection establishment / recovery of the relay terminal on the source indirect path failed.

[0191] In some embodiments, where the first request information is used to request a change of indirect path for a remote terminal, the first request information is carried in any of the following ways:

[0192] The SN modification request message requires modification of the SN message, replacement of the SN message, or release of the SN message. Each of these messages includes a reason for changing the indirect path, and the reason for changing the indirect path includes at least one of the following:

[0193] The N3C interface of the source indirect path failed; the PC5 link quality of the source indirect path was less than the first threshold; an RLF occurred in the source indirect path; a Uu RLF occurred in the relay terminal on the source indirect path; the Uu link quality of the relay terminal on the source indirect path was less than the second threshold; and the Uu connection establishment / recovery of the relay terminal on the source indirect path failed.

[0194] Scenarios for adding or changing indirect paths to remote terminals include any of the following:

[0195] When a remote terminal connects to the first base station via a direct path and to the second base station via an indirect path, including any of the following:

[0196] The indirect path for the remote terminal to switch to another relay terminal under the second base station;

[0197] The remote terminal is switched to another base station, which is a base station that has not established a connection with the remote terminal.

[0198] When a remote terminal connects to the first base station via a direct path, an indirect path to the second base station is added to the remote terminal.

[0199] When a remote terminal connects to the first base station via a direct path and an indirect path, the remote terminal is switched to the indirect path under the second base station while maintaining the direct path under the first base station.

[0200] S202, Send the first response information to the first base station.

[0201] The first response information is used to indicate whether or not to agree to add or change the indirect path for the remote terminal.

[0202] The description of step S202 can be found in the description of step S102 above. It will not be repeated here.

[0203] In some embodiments, after receiving the first request information, the second base station may determine the target relay terminal based on the information of the candidate relay terminals included in the first request information, and send the first indication information to the target relay terminal. The first indication information is used to indicate at least one of the following: adding an indirect path for the remote terminal, configuring the Uu relay RLC channel, and bearer mapping.

[0204] As described above, the second base station can be a base station that the remote terminal connects to via an indirect path, or it can be a base station that has not established a connection with the remote terminal. When the second base station is a base station that the remote terminal connects to via an indirect path, the first indication information is sent to the target relay terminal, corresponding to the scenario described above where the remote terminal switches to another relay terminal under the second base station via an indirect path.

[0205] When the second base station is a base station that has not established a connection with the remote terminal, it sends the first indication information to the target relay terminal, which corresponds to the scenario described above where the remote terminal adds an indirect path to the second base station.

[0206] In some embodiments, such as Figure 5 As shown in the embodiments of this disclosure, another communication method is also provided, applied to a remote terminal, which may include the following steps:

[0207] S301, Receive the first configuration information sent by the first base station.

[0208] The first configuration information is used to configure at least one of the following:

[0209] Remote terminal can add / modify / change indirect paths;

[0210] The identifier of the relay terminal to be added / modified / replaced. The relay terminal to be added / modified / replaced is the target terminal.

[0211] The remote terminal can determine whether to accept the configuration based on the first configuration information and reply with a response message to the first base station.

[0212] Taking the addition of an indirect path as an example, upon receiving the above configuration, the remote terminal associates / establishes a connection with the target terminal based on the first configuration information. If a traffic splitting SRB1 or SRB3 with replication is configured, the remote terminal can further send an SN RRC response message to the SN through the indirect path.

[0213] Taking the indirect path replacement as an example, the remote terminal associates with the target relay terminal. Then, the remote terminal sends an RRC reconfiguration complete message to the first base station. After receiving the RRC reconfiguration complete message from the remote terminal, the first base station sends an SN reconfiguration complete message to the second base station. If a traffic splitting SRB1 or SRB3 with replication is configured, the remote terminal also sends an RRC reconfiguration complete message to the second base station through the target relay terminal.

[0214] In some embodiments, after receiving the first configuration information, the remote terminal performs at least one of the following:

[0215] Stop sending uplink data on the source indirect path;

[0216] End markers are sent to each data radio bearer (DRB) in the indirect path.

[0217] In other words, the remote terminal stops transmitting uplink data on the source indirect path. An end marker can be sent to each DRB on the indirect path so that the first base station knows that the relay terminal on the source indirect path has completed forwarding the remote terminal's uplink data. The remote terminal and the source relay terminal release their association (N3Cout of scope) and no longer send data to each other. The source relay terminal also stops forwarding downlink data to the remote terminal.

[0218] The following example illustrates a complete process for adding or changing indirect paths to remote terminals.

[0219] Taking adding an indirect path to a remote terminal as an example, Figure 6 This is a schematic diagram illustrating the overall flow of a communication method provided in an embodiment of this disclosure. See also... Figure 6 This may include the following steps:

[0220] 0. The remote terminal transmits UL / DL data with the first base station (MN).

[0221] 1. Measurement and reporting are performed between the remote terminal and the first base station (MN).

[0222] 2. The first base station (MN) decides to add an indirect path of another gNB.

[0223] 3. The first base station (MN) sends an SN add request message (MP add request message) to the second base station (SN).

[0224] 4. The relay terminal exchanges RRC reconfiguration messages with the second base station (SN).

[0225] 5. The second base station (SN) sends an SN addition request confirmation message (MP addition confirmation message) to the first base station (MN).

[0226] 5a. The first base station (MN) sends an Xn-U address indication to the second base station (SN).

[0227] That is, send an Xn-U address indication.

[0228] 6. The first base station (MN) sends an RRC reconfiguration message to the remote terminal.

[0229] 7. The remote terminal sends an RRC reconfiguration complete message to the first base station (MN).

[0230] 8. The first base station (MN) sends an SN reconfiguration complete message to the second base station (SN).

[0231] 7a. The remote terminal sends an RRC reconfiguration complete message to the second base station (SN).

[0232] 9. The first base station (MN) sends an SN status transmission (& data forwarding) to the second base station (SN).

[0233] That is, sending SN Status transfer (&data forwarding).

[0234] 10. The second base station (SN) performs the path update process via 5GC.

[0235] In other words, the second base station performs a path update procedure with the 5G core network (5G core, 5GC).

[0236] 11. Transmit UL / DL data between the remote terminal, the first base station (MN), the relay terminal, and the second base station (SN).

[0237] It should be noted that, Figure 6 The dashed lines in the text represent optional steps, that is, steps that are not required to be performed.

[0238] Taking the change of indirect path of a remote terminal as an example, Figure 7 A schematic diagram illustrating the overall flow of another communication method provided in this embodiment of the disclosure. See also... Figure 7 This may include the following steps:

[0239] 0. The remote terminal communicates with the first base station (MN) via UL / DL data through a direct path.

[0240] 0. UL / DL data between the remote terminal and the first base station (MN) via an indirect path.

[0241] That is, the UL / DL data transmitted between the remote terminal and the first base station (MN) through the source relay terminal.

[0242] 1. Measurement and reporting are performed between the remote terminal and the first base station (MN).

[0243] 2. The first base station (MN) decides to change the indirect path (to another base station).

[0244] That is, the first base station (MN) makes a decision on changing the indirect path (to another gNB).

[0245] 3. The first base station (MN) sends an SN add request message (MP add request message) to the second base station (SN).

[0246] 4. The target relay terminal exchanges RRC reconfiguration messages with the second base station (SN).

[0247] 5. The second base station (SN) sends an SN addition request confirmation message (MP addition confirmation message) to the first base station (MN).

[0248] 5a. The first base station (MN) sends an Xn-U address indication to the second base station (SN).

[0249] 6. The first base station (MN) sends an RRC reconfiguration message to the source relay terminal.

[0250] 7. The first base station (MN) sends an RRC reconfiguration message to the remote terminal.

[0251] 8. The remote terminal sends an RRC reconfiguration complete message to the first base station (MN).

[0252] 9. The first base station (MN) sends an SN reconfiguration complete message to the second base station (SN).

[0253] 8a. The remote terminal sends an RRC reconfiguration complete message to the second base station (SN).

[0254] That is, the remote terminal sends an RRC reconfiguration complete message to the second base station (SN) through the target relay terminal.

[0255] 10. The first base station (MN) sends an SN status transmission (& data forwarding) to the second base station (SN).

[0256] That is, sending SN Status transfer (&data forwarding).

[0257] 11. The second base station (SN) performs the path update process via 5GC.

[0258] In other words, the second base station performs a path update procedure with the 5G core network (5G core, 5GC).

[0259] 12. UL / DL data of the remote terminal via the direct path of the first base station.

[0260] This means UL / DL data is transmitted via a direct path from gNB1. gNB1 is the first base station.

[0261] 12. UL / DL data of the remote terminal via the indirect path of the second base station.

[0262] This means that UL and DL data are transmitted via an indirect path in gNB2. gNB2 is the second base station.

[0263] It should be noted that, Figure 7 The dashed lines in the text represent optional steps, that is, steps that are not required to be performed.

[0264] The above embodiments are based on adding or changing indirect paths for remote terminals to ensure service continuity during cross-base station handovers, guaranteeing service reliability, stability, and latency. In some embodiments, when a remote terminal undergoes a cross-base station handover, the direct path of the remote terminal can also be changed to ensure service continuity and guarantee service reliability, stability, and latency. Based on this, in some embodiments, such as... Figure 8 As shown in the embodiments of this disclosure, another communication method is also provided, applied to a first base station, which may include the following steps:

[0265] S401, Send the second request information to the second base station.

[0266] The second request information is used to request that the direct path of the remote terminal be changed to the second base station. The remote terminal connects to the first base station through the direct path and the indirect path.

[0267] In other words, the handover scenario for remote terminals includes remote terminals connecting to the first base station via direct and indirect paths (relay terminals), where the direct path of the remote terminal is switched to the second base station while the indirect path under the first base station is maintained.

[0268] In some embodiments, the second request information is carried in the handover request message, that is, during the HO process, the MN is negotiated to change to the second base station, and the first base station becomes the SN (indirect path).

[0269] The switch request message includes at least one of the following:

[0270] Multipath information under the first base station includes at least one of the following: direct path information and indirect path information;

[0271] Only switch request information for direct paths;

[0272] Request information used to request that the indirect path be maintained as a secondary node (SN);

[0273] Optionally requested / expected new bearerconfig.

[0274] In some embodiments, direct path information and / or indirect path information includes at least one of the following:

[0275] Remote terminal PDU session information, QoS flow information, relay terminal information, Uu relay RLC channel configuration, and bearer mapping.

[0276] In some embodiments, the desired / recommended new bearer configuration includes at least one of the following: MN termination, SN termination bearer, similar to PDU session resource setup Info - SN termination / MN termination.

[0277] S402, Receive the second response information sent by the second base station.

[0278] The second response information is used to indicate whether or not it is agreed to change the direct path of the remote terminal to the second base station.

[0279] After receiving the second request information, the second base station decides whether to accept the handover of the remote terminal and the related handover configuration, and confirms whether to retain the indirect path under the first base station as the SN, and confirms the termination of the MN / SN bearer (PDU session resource establishment information - SN termination / MN termination). Then, it sends a second response information to the first base station. Correspondingly, the first base station receives the second response information sent by the second base station.

[0280] In some embodiments, the second response information is carried in a handover request acknowledgement (HO request Acknowledge) message.

[0281] The switch request confirmation message indicates at least one of the following:

[0282] Whether to accept the switch of remote terminal;

[0283] Switch the relevant configuration;

[0284] Whether to retain the indirect path under the first base station as a secondary node.

[0285] In addition, the second base station can also determine whether to add / retain the SN and decide on the PDU Session ResourceSetup Info – SN terminated / MN terminated; that is, the second base station sends an SN add request message, which contains PDU session resource setup information – SN terminated / MN terminated, while the first base station replies with a response containing PDU session resource setup response information (Resource Setup Response Info) – SN terminated / MN terminated.

[0286] In some embodiments, such as Figure 9 As shown in the embodiments of this disclosure, another communication method is also provided, applied to a second base station, which may include the following steps:

[0287] S501, Receive the second request information sent by the first base station.

[0288] The second request information is used to request that the direct path of the remote terminal be changed to the second base station. The remote terminal connects to the first base station through the direct path and the indirect path.

[0289] S502, Send the second response information to the first base station.

[0290] The second response information is used to indicate whether or not it is agreed to change the direct path of the remote terminal to the second base station.

[0291] for Figure 9 The description of the illustrated embodiments can be referred to the above description of the embodiments. Figure 8The corresponding descriptions in the illustrated embodiments are not repeated here.

[0292] Taking the change of direct path on a remote terminal as an example, Figure 10 This is a schematic diagram illustrating the overall flow of a communication method provided in an embodiment of this disclosure. See also... Figure 10 This may include the following steps:

[0293] 0. The remote terminal and the first base station communicate via a direct path using UL / DL data.

[0294] 0. UL / DL data between the remote terminal and the first base station via an indirect path.

[0295] That is, the UL / DL data transmitted between the remote terminal and the first base station through the source relay terminal.

[0296] 1. Measurement and reporting are performed between the remote terminal and the first base station.

[0297] 2. The first base station decides to change the direct path (to another base station) / MN HO.

[0298] That is, the first base station's decision of changing direct path (to another gNB) / MN HO.

[0299] 3. The first base station sends a HO request message to the second base station (only for direct paths).

[0300] That is, send a HO request (for only direct path).

[0301] 4. The second base station sends an SN add request message to the first base station (for indirect paths).

[0302] That is, send an SN Addition request (for indirect path).

[0303] 5. The first base station sends an SN addition request confirmation message to the second base station (indirect path).

[0304] That is, send SN addition request ack(indirect path).

[0305] 6. The second base station sends a HO confirmation message to the first base station.

[0306] 5a. The first base station sends an Xn-U address indication to the second base station.

[0307] 7. The remote terminal of the first base station sends an RRC reconfiguration message.

[0308] 8. A random access procedure is performed between the remote terminal and the second base station.

[0309] 9. The remote terminal sends an RRC reconfiguration complete message to the second base station.

[0310] 10. The second base station sends an SN reconfiguration complete message to the first base station.

[0311] 11. The first base station sends an SN status transmission (and data forwarding) to the second base station.

[0312] That is, sending SN Status transfer (&data forwarding).

[0313] 12. The second base station performs the path update process via 5GC.

[0314] In other words, the second base station performs a path update procedure with the 5G core network (5G core, 5GC).

[0315] 13. UL / DL data of the remote terminal through the indirect path of the first base station.

[0316] This means UL / DL data is transmitted via an indirect path from gNB1. gNB1 is the first base station.

[0317] 13. UL / DL data of the remote terminal via the direct path of the second base station.

[0318] This means that UL and DL data are transmitted via a direct path through gNB2. gNB2 is the second base station.

[0319] Steps 4-5 can be combined into steps 3 / 6, that is, during the HO process, the MN is negotiated to change to the second base station, and the first base station becomes the SN (indirect path).

[0320] It should be noted that, Figure 10 The dashed lines in the text represent optional steps, that is, steps that are not required to be performed.

[0321] Currently, wireless vehicular networks (V2V) are a high-demand scenario, and cross-base station handovers occur frequently in V2V scenarios. It is crucial to minimize service interruption time during handovers to ensure service continuity. In actual networks, the service interruption time caused by handover is at least 70ms, and in most cases, it exceeds 100ms, significantly impacting the service requirements of V2V. Current technologies for reducing handover interruption time, such as dual active protocol stacks (DAPS), Layer 1 / L2 triggered mobility (LTM), and conditional handover, place high demands on terminals or are complex to implement, potentially hindering commercial deployment. Using UE aggregation to address mobility issues would lower the requirements for individual UEs, offer higher overall reliability, and facilitate commercial deployment.

[0322] Based on application requirements, methods to reduce downtime and ensure service continuity during UE aggregation and cross-base station handover need to be considered. Specifically, during the HO (Hosting On Demand) process, at least one link of remote terminals or relay terminals in the UE aggregation should be maintained to maintain data transmission, thereby meeting the high reliability and low latency service requirements / scenarios such as autonomous driving. Furthermore, cross-base station UE aggregation and cross-base station path management can be considered, supporting these cross-base station path management features to more flexibly handle various UE aggregation or mobility scenarios.

[0323] UE aggregation mobility can be considered in the following scenarios:

[0324] 1) The remote terminal hands over first. During the handover process, the remote terminal maintains data transmission between the source side indirect path and the source base station, and accesses the target base station via a direct Uu link. After the remote terminal accesses the target base station, relay UE handover is performed. After the relay UE handover is completed, data aggregation transmission is resumed. The remote terminal handover process uses a dual PDCP protocol stack, but only one set of RLC / medium access control (MAC) / physical layer (PHY) is used, with an N3C connection between the remote terminal and the relay terminal. This reduces service interruption time during the handover process, achieving almost uninterrupted handover.

[0325] 2) The relay terminal performs the handover first. During the relay terminal handover, the remote terminal transmits data with the source base station gNB1 via a direct path. The remote terminal handover then begins after the relay terminal handover is complete. During the remote terminal handover, the remote terminal maintains the original data transmission between the relay terminal and the source base station gNB1, and connects to the target base station via the relay terminal / indirect path. A dual PDCP protocol stack is used during the remote terminal handover process. After connecting to the target base station, the remote terminal releases the source-side direct path and adds a direct path on the target side, followed by data aggregation and transmission. This reduces service interruption time during the handover process, achieving almost uninterrupted handover.

[0326] 3) When switching between remote terminals and relay terminals simultaneously (i.e., group handover), handover interruption may occur if DAPS is not supported.

[0327] Therefore, in order to reduce service interruption time and ensure service continuity during handover, such as... Figure 11 As shown in the embodiments of this disclosure, another communication method is also provided, applied to a first base station, which may include the following steps:

[0328] S601, Send the second instruction information to the second base station.

[0329] The second indication information is used to indicate the association or aggregation relationship between the remote terminal and the relay terminal. The remote terminal connects to the first base station through direct and indirect paths. The first base station can be understood as the source base station, and the second base station can be understood as the target base station.

[0330] In some embodiments, the remote terminal connects to the first base station via relay terminals on direct and indirect paths, and the handover scenarios for the remote terminal include:

[0331] The remote terminal performs the handover process before the relay terminal. During the handover process, the remote terminal maintains data transmission on the indirect path with the first base station and accesses the second base station through the direct path.

[0332] In some embodiments, the second indication information is carried in a handover request message associated with a relay terminal or an associated handover request message associated with an aggregation terminal.

[0333] When a relay terminal performs a handover procedure before a remote terminal, the handover request message associated with the relay terminal includes at least one of the following:

[0334] The relay terminal is an indication of the relay terminal of the aggregation terminal, the identifier of the remote terminal associated with the relay terminal, the PDU session information of the remote terminal, and the QoS flow information of the remote terminal.

[0335] The identifier of a remote terminal includes at least one of the following:

[0336] The remote terminal is C-RNTI under the first base station;

[0337] The remote terminal is identified by its N3C interface on the first base station.

[0338] In some embodiments, the aggregation terminal includes at least one of the following in the associated handover request message:

[0339] The context information of the remote terminal and the context information of the relay terminal;

[0340] The aggregation relationship between the remote terminal and the relay terminal;

[0341] Remote terminal indication;

[0342] Relay terminal indication;

[0343] Prioritize switching recommendations.

[0344] S602, Receive the third response information sent by the second base station.

[0345] In some embodiments, the second response information is carried in a handover request confirmation message, which includes at least one of the following:

[0346] Configuration of switching commands for remote terminals and relay terminals;

[0347] Priority switching indicator.

[0348] The relay terminal handover command configuration includes the Uu relay RLC channel configuration for forwarding data from remote terminals.

[0349] In other words, in scenarios where the relay terminal performs the handover first and the remote terminal follows, the relay terminal has its own service data. The first base station can inform the second base station of the relay terminal's own service data, such as PDU session / QoS flow information, so that the second base station can perform admission control. However, for relay terminals in UE aggregation, the relay terminal forwards data to remote terminals and needs to obtain Uu resources and Uu Relay RLC channel configuration. The second base station needs to be aware that this is a UE aggregation relay terminal and the service data information of the remote terminal being forwarded by this relay terminal.

[0350] Specifically, during relay terminal handover, the HO request message sent from the first base station to the second base station must include one or more of the following information: the relay terminal indication for UE aggregation, the associated remote terminal identifier (such as the remote terminal's C-RNTI or N3C interface identifier under the source base station), and the remote terminal's PDU session / QoS flow information. Therefore, the handover command configured by the target base station for the relay terminal may also include the Uu RelayRLC channel configuration for forwarding remote terminal data. Thus, at the earliest possible time after the handover between the relay terminal and the remote terminal is completed, the relay terminal can forward data for the remote terminal and resume the remote terminal's data aggregation transmission.

[0351] In other words, under UE aggregation, regardless of whether the remote terminal or the relay terminal initiates the handover first, the target base station needs to know the association / aggregation relationship between the remote terminal and the relay terminal, as well as the PDU session / QoS flow information of the remote terminal. The admission control of the second base station needs to consider the service QoS information of the remote terminal. Therefore, a HO request / acknowledgment process can be used to implement the handover of the remote terminal and the relay terminal in UE aggregation; that is, this HO process is for this UE pair. Specifically, the HO request message contains the following information: context information of both the remote terminal and the relay terminal, the aggregation relationship between the remote terminal and the relay terminal, remote terminal / relay terminal indication, and priority handover suggestion (suggesting whether to handover the remote terminal or the relay terminal first). The handover request confirmation message contains the following information: HO command configuration of both the remote terminal and the relay terminal, and priority handover indication (indicating whether to handover the remote terminal or the relay terminal first). Although the first base station receives HO commands from two terminals, it performs a serial handover on the air interface. Assuming the relay terminal is switched first, the first base station needs to wait for the relay terminal to complete the switch and receive the instruction from the second base station before configuring the remote terminal to switch (even though it has already obtained the HO command information of the remote terminal beforehand).

[0352] based on Figure 11 In the illustrated embodiment, the second indication information is used to indicate the association or aggregation relationship between the remote terminal and the relay terminal, so that the second base station can determine the association or aggregation relationship between the remote terminal and the relay terminal based on the second indication information. Subsequently, when the remote terminal and / or the relay terminal switches to the second base station, since the second base station has already learned about the association or aggregation relationship between the remote terminal and the relay terminal, the second base station can promptly accept the switch of the remote terminal and / or the relay terminal, thereby reducing service interruption time and ensuring service continuity during the switch.

[0353] In some embodiments, such as Figure 12As shown, this disclosure also provides another communication method applied to a second base station, which may include the following steps:

[0354] S701, Receive the second indication information sent by the first base station.

[0355] The second indication information is used to indicate the association or aggregation relationship between the remote terminal and the relay terminal, and the remote terminal connects to the first base station through direct and indirect paths.

[0356] S702, Send the third response information to the first base station and the second base station.

[0357] for Figure 12 The description of the illustrated embodiments can be referred to the above description of the embodiments. Figure 11 The corresponding descriptions of the embodiments shown are not repeated here.

[0358] In some embodiments, such as Figure 13 As shown, this disclosure also provides another communication method applied to a remote terminal, which may include the following steps:

[0359] S801, in response to handover failure, sends third indication information to the first base station via an indirect path or offloading signaling radio bearer.

[0360] The third indication information is used to indicate a handover failure. The remote terminal connects to the first base station via a direct path and an indirect path. During the handover process, the remote terminal maintains data transmission on the indirect path with the first base station and accesses the second base station via the direct path. A handover failure occurs when the remote terminal fails to switch to the second base station via the direct path.

[0361] In some embodiments, when a remote terminal connects to a first base station via a direct path and an indirect path, and when the remote terminal changes its direct path, during the handover process, the remote terminal maintains data transmission on the indirect path with the first base station and accesses the second base station via the direct path. If a handover failure is detected, i.e., a failure to handover to the second base station via the direct path, a third indication message is sent to the first base station via the indirect path or a offloading signaling radio bearer in response to the handover failure. Accordingly, the first base station receives the third indication message sent by the remote terminal and, based on the third indication message, determines that the remote terminal's handover has failed and performs master cell group (MCG) recovery.

[0362] In this way, during the handover process of the remote terminal, the remote terminal maintains data transmission on the indirect path with the first base station and accesses the second base station through the direct path. This ensures that even if the handover of the remote terminal fails, the remote terminal can still transmit data based on the indirect path with the first base station, thereby reducing service interruption time and ensuring service continuity.

[0363] In some embodiments, the third indication information is carried in the primary cell group failure information (MCG failure information).

[0364] In other words, in scenarios where the remote terminal hands over first, during the handover process, the remote terminal maintains data transmission between the source-side indirect path and the source base station, and accesses the target base station via a direct Uu link. The remote terminal's SRBs and direct data bearer on the source side are suspended (MAC reset, RLC / PDCP waiting for re-establishment). When the remote terminal receives a handover command, it resets the MAC and accesses the target base station. Therefore, when the HO fails, it's equivalent to the underlying / direct link with the source base station no longer existing, only the indirect path remains. The remote terminal can notify the source base station of the HO failure via the indirect path / shunting SRB1 (reusing the MCG Failure Information), meaning the MCG Failure Information indicates HO failure and initiates MCG recovery.

[0365] The foregoing primarily describes the solution provided in this disclosure from the perspective of interaction between various nodes. It is understood that each node, such as a remote terminal, a first base station, or a second base station, includes corresponding hardware structures and / or software modules to perform the aforementioned functions. Those skilled in the art should readily recognize that, based on the algorithmic steps of the examples described in conjunction with the embodiments disclosed herein, this disclosure can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed in hardware or by computer software driving hardware depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this disclosure.

[0366] This disclosure embodiment can divide the remote terminal, the first base station, or the second base station into functional modules according to the above method embodiment. For example, each function can be divided into a separate functional module, or two or more functions can be integrated into one functional module. The integrated module can be implemented in hardware or software. It should be noted that the module division in this disclosure embodiment is illustrative and only represents one logical functional division; other division methods may be used in actual implementation. The following description uses the example of dividing each functional module according to each function.

[0367] Figure 14 This is a schematic diagram illustrating the composition of a communication device provided in an embodiment of this disclosure. Figure 14 As shown, the communication device 90 includes a transmitting unit 901 and a receiving unit 902.

[0368] The communication device 90 can be the first base station or a chip within the first base station. When the communication device 90 is used to implement the functions of the first base station in the above embodiments, each unit is specifically used to implement the following functions.

[0369] The sending unit 901 is used to send a first request information to the second base station. The first request information is used to request the addition or replacement of the indirect path for the remote terminal.

[0370] The receiving unit 902 is used to receive first response information sent by the second base station. The first response information is used to indicate whether it agrees to add or change the indirect path for the remote terminal.

[0371] In some embodiments, the sending unit 901 is specifically configured to: acquire a measurement report, the measurement report including the identifier and serving cell of at least one candidate relay terminal; determine, based on the measurement report, whether to add or change an indirect path between the remote terminal and the second base station; and, in response to determining to add or change an indirect path between the remote terminal and the second base station, send a first request message to the second base station.

[0372] In some embodiments, the sending unit 901 is further configured to send first configuration information to the remote terminal, the first configuration information being configured to configure at least one of the following: the remote terminal adding / modifying / replacing an indirect path; and the identifier of the relay terminal to be added / modified / replacing.

[0373] Figure 15 This is a schematic diagram illustrating the composition of another communication device provided in an embodiment of this disclosure. (See diagram below.) Figure 15 As shown, the communication device 100 includes a receiving unit 1001 and a transmitting unit 1002.

[0374] The communication device 100 can be the second base station or a chip within the second base station. When the communication device 100 is used to implement the functions of the second base station in the above embodiments, each unit is specifically used to implement the following functions.

[0375] The receiving unit 1001 is used to receive first request information sent by the first base station, the first request information being used to request the addition or replacement of an indirect path for the remote terminal;

[0376] The sending unit 1002 is used to send first response information to the first base station. The first response information is used to indicate whether it agrees to add or change the indirect path for the remote terminal.

[0377] In some embodiments, the sending unit 1002 is further configured to determine the target relay terminal based on the information of the candidate relay terminals, and send first indication information to the target relay terminal. The first indication information is used to indicate at least one of the following: adding an indirect path for the remote terminal, configuring the Uu relay RLC channel, and bearer mapping.

[0378] Figure 16 This is a schematic diagram illustrating the composition of another communication device provided in an embodiment of this disclosure. (See diagram below.) Figure 16 As shown, the communication device 110 includes a receiving unit 1101. In some embodiments, the communication device 110 further includes a transmitting unit 1102.

[0379] The communication device 110 can be the aforementioned remote terminal or a chip within the remote terminal. When the communication device 110 is used to implement the functions of the remote terminal in the above embodiments, each unit is specifically used to implement the following functions.

[0380] The receiving unit 1101 is configured to receive first configuration information sent by the first base station, wherein the first configuration information is used to configure at least one of the following:

[0381] Remote terminal can add / modify / change indirect paths;

[0382] The identifier of the relay terminal to be added / modified / replaced.

[0383] The transmitting unit 1102 is used for at least one of the following:

[0384] Stop sending uplink data on the source indirect path;

[0385] End markers are sent to each data radio bearer (DRB) in the indirect path.

[0386] Figure 17 This is a schematic diagram illustrating the composition of another communication device provided in an embodiment of this disclosure. (See diagram below.) Figure 17 As shown, the communication device 120 includes a transmitting unit 1201 and a receiving unit 1202.

[0387] The communication device 120 can be the first base station or a chip in the first base station. When the communication device 120 is used to implement the functions of the first base station in the above embodiments, each unit is specifically used to implement the following functions.

[0388] The sending unit 1201 is used to send a second request information to the second base station. The second request information is used to request that the direct path of the remote terminal be changed to the second base station. The remote terminal connects to the first base station through the direct path and the indirect path.

[0389] The receiving unit 1202 is used to receive second response information sent by the second base station. The second response information is used to indicate whether it agrees to change the direct path of the remote terminal to the second base station.

[0390] Figure 18 This is a schematic diagram illustrating the composition of another communication device provided in an embodiment of this disclosure. (See diagram below.) Figure 18 As shown, the communication device 130 includes a receiving unit 1301 and a transmitting unit 1302.

[0391] The communication device 130 can be the second base station or a chip within the second base station. When the communication device 130 is used to implement the functions of the second base station in the above embodiments, each unit is specifically used to implement the following functions.

[0392] The receiving unit 1301 is used to receive a second request information sent by the first base station. The second request information is used to request that the direct path of the remote terminal be changed to the second base station. The remote terminal connects to the first base station through a direct path and an indirect path.

[0393] The sending unit 1302 is used to send a second response information to the first base station, the second response information being used to indicate whether it agrees to change the direct path of the remote terminal to the second base station.

[0394] Figure 19 This is a schematic diagram illustrating the composition of another communication device provided in an embodiment of this disclosure. (See diagram below.) Figure 19 As shown, the communication device 140 includes a transmitting unit 1401 and a receiving unit 1402.

[0395] The communication device 140 can be the first base station or a chip in the first base station. When the communication device 140 is used to implement the functions of the first base station in the above embodiments, each unit is specifically used to implement the following functions.

[0396] The sending unit 1401 is used to send second indication information to the second base station. The second indication information is used to indicate the association or aggregation relationship between the remote terminal and the relay terminal. The remote terminal is connected to the first base station through a direct path and an indirect path.

[0397] The receiving unit 1402 is used to receive the third response information sent by the second base station.

[0398] Figure 20 This is a schematic diagram illustrating the composition of another communication device provided in an embodiment of this disclosure. (See diagram below.) Figure 20 As shown, the communication device 150 includes a receiving unit 1501 and a transmitting unit 1502.

[0399] The communication device 150 can be the second base station or a chip within the second base station. When the communication device 150 is used to implement the functions of the second base station in the above embodiments, each unit is specifically used to implement the following functions.

[0400] The receiving unit 1501 is used to receive second indication information sent by the first base station. The second indication information is used to indicate the association or aggregation relationship between the remote terminal and the relay terminal. The remote terminal is connected to the first base station through a direct path and an indirect path.

[0401] The sending unit 1502 is used to send third response information to the second base station.

[0402] Figure 21 This is a schematic diagram illustrating the composition of another communication device provided in an embodiment of this disclosure. (See diagram below.) Figure 21 As shown, the communication device 160 includes a transmitting unit 1601.

[0403] The communication device 160 can be the aforementioned remote terminal or a chip within the remote terminal. When the communication device 160 is used to implement the functions of the remote terminal in the above embodiments, each unit is specifically used to implement the following functions.

[0404] The transmitting unit 1601 is used to send third indication information to the first base station via an indirect path or a split signaling radio bearer in response to a handover failure. The third indication information is used to indicate a handover failure. The remote terminal is connected to the first base station via a direct path and an indirect path. During the handover process of the remote terminal, the remote terminal maintains data transmission on the indirect path with the first base station and accesses the second base station via the direct path.

[0405] It should be noted that, Figures 14 to 21 The units within can also be called modules; for example, a transmitting unit can be called a transmitting module. Additionally, in... Figures 14 to 21 In the embodiments shown, the names of the various units may not be the same as those shown in the figures. For example, the transmitting unit may also be called the communication unit, and the receiving unit may also be called the communication unit.

[0406] Figures 14 to 21If the various units in the present disclosure are implemented as software functional modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solutions of the embodiments of this disclosure, in essence, or the parts that contribute to the prior art, or all or part of the technical solutions, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) or processor to execute all or part of the steps of the methods of the various embodiments of this disclosure. Storage media for storing computer software products include various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0407] When any one of the communication devices 90 to 160 described above implements the function of the integrated module in hardware, this disclosure provides a schematic diagram of the structure of a communication device. For example... Figure 22 As shown, the communication device 170 includes: a processor 1702, a communication interface 1703, and a bus 1704. Optionally, the communication device 170 may also include a memory 1701.

[0408] Processor 1702 may implement or execute various exemplary logic blocks, modules, and circuits described in conjunction with this disclosure. Processor 1702 may be a central processing unit, a general-purpose processor, a digital signal processor, an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. It may implement or execute various exemplary logic blocks, modules, and circuits described in conjunction with this disclosure. Processor 1702 may also be a combination of functions implementing computation, such as a combination of one or more microprocessors, a combination of a DSP and a microprocessor, etc.

[0409] The communication interface 1703 is used to connect to other devices via a communication network. This communication network can be Ethernet, wireless access network, wireless local area network (WLAN), etc.

[0410] The memory 1701 may be a read-only memory (ROM) or other type of static storage device capable of storing static information and instructions, random access memory (RAM) or other type of dynamic storage device capable of storing information and instructions, or electrically erasable programmable read-only memory (EEPROM), disk storage media or other magnetic storage devices, or any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer, but is not limited thereto.

[0411] As one possible implementation, the memory 1701 can exist independently of the processor 1702. The memory 1701 can be connected to the processor 1702 via a bus 1704 and is used to store instructions or program code. When the processor 1702 calls and executes the instructions or program code stored in the memory 1701, it can implement the communication method provided in the embodiments of this disclosure.

[0412] In another possible implementation, the memory 1701 can also be integrated with the processor 1702.

[0413] The 1704 bus can be an extended industry standard architecture (EISA) bus, etc. The 1704 bus can be divided into address bus, data bus, control bus, etc. For ease of representation, Figure 22 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0414] Through the above description of the implementation methods, those skilled in the art can clearly understand that, for the sake of convenience and brevity, only the division of the above functional modules is used as an example. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the remote terminal, the first base station, or the second base station can be divided into different functional modules to complete all or part of the functions described above.

[0415] This disclosure also provides a computer-readable storage medium. All or part of the processes in the above method embodiments can be executed by computer instructions instructing related hardware. The program can be stored in the computer-readable storage medium, and when executed, it can include the processes of the above method embodiments. The computer-readable storage medium can also be an external storage device of the remote terminal, the first base station, or the second base station, such as a pluggable hard drive, smart media card (SMC), secure digital card (SD), flash card, etc., equipped on the remote terminal, the first base station, or the second base station. Further, the computer-readable storage medium can include both internal storage units of the remote terminal, the first base station, or the second base station and external storage devices. The computer-readable storage medium is used to store the computer program and other programs and data required by the remote terminal, the first base station, or the second base station. The computer-readable storage medium can also be used to temporarily store data that has been output or will be output.

[0416] This disclosure also provides a computer program product comprising a computer program that, when run on a computer, causes the computer to perform any of the communication methods provided in the above embodiments.

[0417] Although this disclosure has been described herein in conjunction with various embodiments, those skilled in the art will understand and implement other variations of the disclosed embodiments by reviewing the accompanying drawings, the disclosure, and the appended claims in carrying out the claimed disclosure. In the claims, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude a plurality. A single processor or other unit can implement several functions listed in the claims. While different dependent claims may recite certain measures, this does not mean that these measures cannot be combined to produce a good effect.

[0418] Although this disclosure has been described in conjunction with specific features and embodiments, it will be apparent that various modifications and combinations can be made therein without departing from the spirit and scope of this disclosure. Accordingly, this specification and drawings are merely exemplary illustrations of the disclosure as defined by the appended claims and are to be considered as covering any and all modifications, variations, combinations, or equivalents within the scope of this disclosure. It is obvious that those skilled in the art can make various alterations and modifications to this disclosure without departing from its spirit and scope. Thus, this disclosure is also intended to include any such modifications and modifications that fall within the scope of the claims of this disclosure and their equivalents.

[0419] The above are merely specific embodiments of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any changes or substitutions within the technical scope disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A communication method, characterized in that, Applied to a first base station, the method includes: Send a first request message to the second base station, the first request message being used to request the addition or replacement of an indirect path for the remote terminal; The system receives a first response message sent by the second base station, the first response message being used to indicate whether it agrees to add or change an indirect path for the remote terminal.

2. The method according to claim 1, characterized in that, The first request information includes information about the candidate relay terminal.

3. The method according to claim 1, characterized in that, When the first request information is used to request the addition of the indirect path to the remote terminal, the first request information carries any of the following: The auxiliary node add request message and the Xn interface multipath add request message include a candidate relay terminal list.

4. The method according to claim 3, characterized in that, The auxiliary node add request message also includes at least one of the following: Add an indicator to the indirect path; Source indirect path related information; Identification of the source relay terminal; Bearer mapping; Uu relay radio link control (RLC) channel configuration.

5. The method according to claim 3, characterized in that, The auxiliary node addition request message also includes a triggering reason for adding the auxiliary node, and the triggering reason for adding the auxiliary node includes at least one of the following: Adding / modifying / switching indirect paths in multipath communication; N3C indirect path addition / modification / switching; Add / modify / switch side link SL indirect paths; The reason for changing the indirect path includes at least one of the following: The N3C interface of the source indirect path fails; the PC5 link quality of the source indirect path is less than a first threshold; a radio link failure (RLF) occurs on the PC5 link of the source indirect path; a Uu RLF occurs on the relay terminal on the source indirect path; the Uu link quality of the relay terminal on the source indirect path is less than a second threshold; and the Uu connection establishment / recovery of the relay terminal on the source indirect path fails.

6. The method according to claim 1, characterized in that, When the first request information is used to request a change of the indirect path for the remote terminal, the first request information carries any of the following: The SN modification request message requires modification of the SN message, replacement of the SN message, or release of the SN message. Each of these messages includes a reason for changing the indirect path, and the reason for changing the indirect path includes at least one of the following: The N3C interface of the source indirect path fails; the PC5 link quality of the source indirect path is less than a first threshold; an RLF occurs in the source indirect path; a Uu RLF occurs in the relay terminal on the source indirect path; the Uu link quality of the relay terminal on the source indirect path is less than a second threshold; and the Uu connection establishment / recovery of the relay terminal on the source indirect path fails.

7. The method according to claim 1, characterized in that, Sending the first request information to the second base station includes: Obtain a measurement report, which includes the identifier of at least one candidate relay terminal and the serving cell; Based on the measurement report, determine whether to add or replace the indirect path between the remote terminal and the second base station; In response to determining that an indirect path between the remote terminal and the second base station has been added or changed, the first request information is sent to the second base station.

8. The method according to claim 1, characterized in that, The method further includes: Send first configuration information to the remote terminal, wherein the first configuration information is used to configure at least one of the following: The remote terminal can add, modify, or change indirect paths; The identifier of the relay terminal to be added / modified / replaced.

9. The method according to claim 1, characterized in that, The scenarios for adding or changing indirect paths for remote terminals include any of the following: When the remote terminal is connected to the first base station via a direct path, an indirect path to the second base station is added to the remote terminal. When the remote terminal is connected to the first base station via a direct path and an indirect path, the remote terminal is switched to the indirect path under the second base station while maintaining the direct path under the first base station. When the remote terminal is connected to the first base station via a direct path and to the second base station via an indirect path, the indirect path of the remote terminal is changed to another relay terminal under the second base station, while maintaining the direct path with the first base station; When the remote terminal is connected to the first base station via a direct path and to the third base station via an indirect path, the remote terminal is switched to the indirect path under the second base station while maintaining the direct path under the first base station.

10. A communication method, characterized in that, Applied to a second base station, the method includes: Receive a first request information sent by a first base station, the first request information being used to request the addition or replacement of an indirect path for a remote terminal; Send a first response message to the first base station, the first response message being used to indicate whether to agree to add or change the indirect path for the remote terminal.

11. The method according to claim 10, characterized in that, The first request information includes information about the candidate relay terminal.

12. The method according to claim 11, characterized in that, The method further includes: Based on the information of the candidate relay terminals, a target relay terminal is determined, and a first indication message is sent to the target relay terminal. The first indication message is used to indicate at least one of the following: Add an indirect path to the remote terminal, configure the Uu relay RLC channel, and perform bearer mapping.

13. A communication method, characterized in that, Applied to a remote terminal, the method includes: Receive first configuration information sent by a first base station, wherein the first configuration information is used to configure at least one of the following: The remote terminal can add, modify, or change indirect paths; The identifier of the relay terminal to be added / modified / replaced.

14. The method according to claim 13, characterized in that, The method further includes at least one of the following: Stop sending uplink data on the source indirect path; End markers are sent to each data radio bearer (DRB) in the indirect path.

15. A communication method, characterized in that, Applied to a first base station, the method includes: Send a second request message to the second base station. The second request message is used to request that the direct path of the remote terminal be changed to the second base station. The remote terminal is connected to the first base station through a direct path and an indirect path. The system receives a second response message sent by the second base station, the second response message indicating whether it agrees to change the direct path of the remote terminal to the second base station.

16. The method according to claim 15, characterized in that, The second request information is carried in a handover request message, which includes at least one of the following: The multipath information under the first base station includes at least one of the following: direct path information and indirect path information; Only switch request information for direct paths; Used to request information that keeps the indirect path as a secondary node; Expected / Recommended new bearer configuration.

17. The method according to claim 16, characterized in that, The direct path information and / or the indirect path information include at least one of the following: The remote terminal's Protocol Data Unit (PDU) session information, Quality of Service (QoS) flow information, relay terminal information, Uu relay RLC channel configuration, and bearer mapping.

18. The method according to claim 15, characterized in that, The second response information is carried in a handover request confirmation message, which indicates at least one of the following: Whether to accept the switch of the remote terminal; Switch the relevant configuration; Whether to retain the indirect path under the first base station as a secondary node.

19. A communication method, characterized in that, Applied to a second base station, the method includes: The system receives a second request message sent by the first base station. The second request message is used to request that the direct path of the remote terminal be changed to the second base station. The remote terminal is connected to the first base station through a direct path and an indirect path. A second response message is sent to the first base station, the second response message indicating whether it agrees to change the direct path of the remote terminal to the second base station.

20. A communication method, characterized in that, Applied to a first base station, the method includes: Send a second indication message to the second base station. The second indication message is used to indicate the association or aggregation relationship between the remote terminal and the relay terminal. The remote terminal is connected to the first base station through a direct path and an indirect path. Receive the third response information sent by the second base station.

21. The method according to claim 20, characterized in that, The second indication information is carried in the handover request message associated with the relay terminal or the handover request message associated with the aggregation terminal.

22. The method according to claim 21, characterized in that, When the relay terminal performs a handover process before the remote terminal, the handover request message associated with the relay terminal includes at least one of the following: The relay terminal is an indication of the relay terminal of the aggregation terminal, the identifier of the remote terminal associated with the relay terminal, the PDU session information of the remote terminal, and the QoS flow information of the remote terminal.

23. The method according to claim 22, characterized in that, The identifier of the remote terminal includes at least one of the following: The remote terminal uses the cell wireless network temporary identifier (C-RNTI) under the first base station; The remote terminal is identified by its N3C interface on the first base station.

24. The method according to claim 21, characterized in that, The aggregation terminal's associated handover request message includes at least one of the following: The context information of the remote terminal and the context information of the relay terminal; The aggregation relationship between the remote terminal and the relay terminal; Remote terminal indication; Relay terminal indication; Prioritize switching recommendations.

25. The method according to claim 20, characterized in that, The third response information is carried in a handover request confirmation message, which includes at least one of the following: The switching command configuration of the remote terminal and the switching command configuration of the relay terminal; Priority switching indicator.

26. The method according to claim 25, characterized in that, The relay terminal's handover command configuration includes a Uu relay RLC channel configuration for forwarding data from the remote terminal.

27. The method according to claim 20, characterized in that, The remote terminal connects to the first base station via relay terminals on direct and indirect paths. The handover scenarios for the remote terminal include: The remote terminal performs a handover process before the relay terminal. During the handover process of the remote terminal, the remote terminal maintains data transmission on the indirect path with the first base station and accesses the second base station through the direct path.

28. A communication method, characterized in that, Applied to a second base station, the method includes: The system receives a second indication information sent by a first base station. The second indication information is used to indicate the association or aggregation relationship between a remote terminal and a relay terminal. The remote terminal is connected to the first base station through a direct path and an indirect path. Send a third response message to the second base station.

29. A communication method, characterized in that, Applied to a remote terminal, the method includes: In response to a handover failure, a third indication message is sent to the first base station via an indirect path or a split signaling radio bearer. The third indication message is used to indicate a handover failure. The remote terminal is connected to the first base station via a direct path and an indirect path. During the handover process of the remote terminal, the remote terminal maintains data transmission on the indirect path with the first base station and accesses the second base station via the direct path.

30. A communication device, characterized in that, include: Memory and processor; Memory and processor are coupled; The memory is used to store instructions that can be executed by the processor; When the processor executes the instructions, it performs the method as described in any one of claims 1 to 29.

31. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions that, when executed on a computer, cause the computer to perform the method as described in any one of claims 1 to 29.

32. A computer program product, characterized in that, The computer program product includes computer instructions that, when executed on a computer, cause the computer to perform the method as described in any one of claims 1 to 29.

Images